The long term objective of this research work is to gain a better understanding of the molecular mechanisms involved in the translation of genetic messages in a mammalian cell. The near term objective is to study the mechanism of protein synthesis initiation in cell-free systems from mammalian cells (such as rabbit reticulocytes, and rat liver) and the requirements of different protein factors involved in this process. Once we gain a better understanding of the roles of different protein factors in protein synthesis in animal cells, we plan to extend these studies to determine how these factors change under different physiological conditions and in the presence of hormones. BIBLIOGRAPHIC REFERENCES: Gupta, N. K., Chatterjee, B., Chen, Y. C., and Majumdar, A., Protein Synthesis in Rabbit Reticulocytes XI: A Study of Met-tRNAfMet Binding Factor(s) and Met-tRNAfMet Binding to Ribosomes and AUG Codon, J. Biol. Chem., 250, 853-862 (1975). Gupta, N. K., Chatterjee, B., and Majumdar, A., Protein Synthesis in Rabbit Reticulocytes XII: Requirement of mRNA (AUG Codon) for Met-tRNAfMet Binding to 40S Ribosomes, Biochem. Biophys. Res. Commun., 65, 797-805 (1975).